The rookie wide receivers gave their best imitation Thursday, running some of the routes the Chargers anticipate seeing Monday night. They scampered back to the line of scrimmage, ran another route, scampered back, ran another, over and over and over.

Whew.

Welcome to life on the practice squad.

In pads, the Chargers had their first preparation day Thursday to be devoted entirely to the season opener. It required a ragged practice for the team's 10-man practice squad, particularly those tasked with giving the defense a look at the Cardinals' wide receiver corps.

Others like Dontrelle Inman, a wide receiver on the 53-man roster, also assisted the scout team. He was rookie John Brown.

"They had to dig down deep today," coach Mike McCoy said, acknowledging brief breaks had to be taken. "That's their job. The skill positions more than the linemen obviously, they've got a lot of running to do, and it gets even worse (Friday). We're playing a lot of three-receiver sets, four and five wides at times week to week. ... It's a track meet for them.

"They did a good job with it. That's why we condition you. You condition all throughout training camp, and you're a young player. We say, 'This is your job. You've got to do it the right way.'"

Their jobs could change.

San Diego has only five wide receivers on its 53-man roster, but Herndon essentially serves as a sixth, likely one injury away from being promoted. Same goes on the offensive line. The team kept only eight linemen, but there is Jeremiah Sirles, a tackle-guard from Nebraska.

It is important for practice-squad players to present a good look when tasked.

Also prudent is they work on their own technique, developing for the possibility they someday play an opponent instead of simply "playing" one.

"We've got two great examples of when you have the right approach to being a practice-squad player or college free agent (what can happen): Malcom Floyd and Antonio Gates," McCoy said. "You see the way the number of years they've had in this league; they still practice the same way. As a young player, we've told them all along, it doesn't matter how you got here. You're here on this team, whether it's the 53-man roster or 10-man practice squad. It's a tough business, so you've got to do it the right way every day."

Because of the Monday game, the team has an extra day in its work week.

Thursday essentially was a Wednesday in the Chargers' normal routine, working in pads, doing a tackling circuit, and largely installing the gameplan.

Nuts 'n' Bolts

• Safety Jahleel Addae (hamstring) and cornerback Chris Davis (ankle) were the only Chargers to miss practice due to medical reasons. Nick Hardwick also was a spectator, but get used to that. The veteran center is expected to miss one practice each week all season, helping preserve him from unnecessary wear and tear. The coaches are expected to apply a similar plan with other players.

• The team will travel 20,274 miles this regular season, sixth most in the NFL, according to the league. It is the fewest miles for the team in years, though, having logged 26,932 miles in 2013 and 25,766 in 2012. The team has the NFC West on the schedule, featuring short trips to Santa Clara and Glendale. The Raiders, at 36,078 miles, will travel the farthest this year. They play once in London.